The Airports, Air Quality, and Asthma (AAA) Study
ConditionPediatric Asthma
Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexAll
Age6-12
SponsorUniversity of Washington
About this trial
For children with asthma, exposure to indoor air pollution increases the risk of a serious asthma exacerbation, which can be life-threatening. Interventions aimed at improving indoor air quality, including use of a portable air cleaner with a high-efficiency particulate air (HEPA) filter, can reduce this risk, but the effectiveness, feasibility and acceptability of HEPA air cleaners varies by setting. In collaboration with a community health worker (CHW) delivered asthma education program, the investigators are conducting a randomized clinical trial to evaluate the effectiveness of HEPA air cleaners to improve indoor air quality and child asthma health in South King County of Washington state, a vulnerable community impacted by air pollution from airports and highway traffic. Key features of the Airports, Air Quality and Asthma (AAA) design include integration of CHWs into study procedures, including CHWs recruited from community-based organizations, into multiple aspects of the trial protocol. The investigators aim to recruit up to N=60 children with asthma randomized into intervention and control groups in a 1:1 ratio, conduct baseline assessments of indoor air quality and airway health, and collect repeated assessments of air quality and airway health during the three-month intervention period and after the trial concludes. Study findings will inform future approaches to integrate HEPA air cleaners into existing CHW asthma education programs in this and similar communities.
Eligibility criteria
This trial does not accept healthy volunteersQualifiers
Child is 6-12 years old with a health care provider-diagnosed asthma.
Caregiver is comfortable in participating in all study activities in English (communicating with study staff by phone and completing online surveys).
Caregiver is familiar with the child's daily asthma health.
Residence within 10 miles of Seattle-Tacoma International Airport as determined by zip code
Disqualifiers
Child has severe asthma at baseline. Severe asthma was defined in consultation with pediatric pulmonologists to be caregiver-reported asthma symptoms every day over the past 14 days and/or two or more inpatient hospitalizations for asthma in the past 12 months.
Households were excluded if there were multiple individuals within the same household with asthma eligible for the King County CHW Asthma Program or had severe asthma.
Trial design
Design model
Parallel
Treatments tested in this trial
Portable air cleaner with HEPA filter
DeviceThe Winix 9800 is a true HEPA air cleaner that has been AHAM (Association of Home Appliance Manufacturers) Verifide® for rooms that are 500 square feet in size. The air cleaner has a washable fine mesh pre-filter that captures large airborne particles, an activated carbon filter that reduces volatile organic compounds and odors, and a true HEPA filter that captures 99.99% of airborne allergens as small as 0.003 microns in size.
Less effective portable air cleaner (no HEPA)
DeviceWinix 9800 air cleaner, with data logging energy use monitor is installed in the child's bedroom. In the sham group, the Winix 9800 true HEPA filter and activated carbon filter were removed. This was an internal modification and not visible to the user. The air cleaner still included a washable fine mesh pre-filter that captures large airborne particles.
Treatment groups
60 Participants
are divided into 2 treatment groupsGroup A: Effective portable air cleaner (HEPA)Experimental treatment 1 intervention
Group B: Control portable air cleaner (less effective).Sham comparator 1 intervention
Trial outcomes
Primary outcomes
1
Symptom days over 7 days
Symptom days were assessed through brief weekly online surveys sent to caregivers. A symptom-day was defined as any day in the past week when the child had asthma symptoms or used quick-relief medication. Caregivers reported the number of days with symptoms (e.g., coughing, wheezing, shortness of breath, nighttime awakenings), any unscheduled medical visits, and whether the child had a respiratory infection. They also noted how many nights the child slept at home, any issues with the indoor air cleaner, and its usage frequency. Symptom scores ranged from 0 to 7, with high scores indicating more days experienced for that symptom. Study staff monitored the weekly caregiver survey to ensure that the child's symptoms were not worsening over the course of the study.
Time frame
Repeated measure, assessed on a weekly basis throughout the 3 month observation period.2
Change in Asthma Control Score
The Child Asthma Control Test (C-ACT) is a short seven-question survey used to characterize child asthma control based on parent and child report of symptoms over the prior 30 days. The C-ACT has been validated for ages 4-11 years old and shown to have good psychometric properties. A C-ACT score is calculated based on responses, ranging from 0 to 27, with higher values reflecting better asthma control, and a score of 19 or lower considered to reflect inadequate, or "poor," control. This test is administered at the beginning and at the end of the research study. The change in child Asthma Control Test (C-ACT) score between baseline and post-intervention is used to assess the benefit of reducing indoor air pollution in the child's bedroom. Study team staff review responses on the baseline survey to address missing data or participant confusion during the study visit.
Time frame
From the baseline visit until the end of study follow-up, 3 months later.Sponsors and contacts
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Source ClinicalTrials.gov